Plasmon scattering from a single gold nanoparticle collected through an optical fiber

A single gold nanoparticle is attached to the end of a chemically etched fiber axicon microlens tip by modifying the tip surface with linker molecules. The high collection efficiency of the fiber axicon microlens allows plasmon scattering of a single nanoparticle to be measured directly through the optical fiber. The portable nature of this probe allows direct optical sensing of environmental changes using a single nanoparticle.